@article{TM_1967_88_a5,
     author = {N. I. Chernykh},
     title = {Jackson's inequality in $L_2$},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {71--74},
     publisher = {mathdoc},
     volume = {88},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1967_88_a5/}
}